Questions tagged [linear-systems]
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8
questions
1
vote
1answer
25 views
Linear Nastran model not converging
I am running a SOL 101 linear statics FEA. If I fix down the whole geometry it converges. But anything less than around 90% fix down and it will sit there crunching away at the numbers forever. This ...
1
vote
0answers
40 views
Lyaponuv stability condition of linear systems for homogenous P in V(x) = x^T P x
I am currently learning about using Lyaponuv functions to find Linear Matrix Inequalities (LMIs) as conditions for stability of a linear time invariant system.
i.e.
$$
\dot{x}(t) = Ax(t)
$$
is stable ...
1
vote
0answers
39 views
LQR control effort / control bandwidth relationship
I'm working with a linear system, having given matrices A and B
$$A = \left[\begin{array}{cc} 0 & 1 \\ -0.9 & 0 \end{array}\right]$$
$$B = \left[\begin{array}{c} 0 \\ 2 \end{array}\right]$$
...
0
votes
1answer
34 views
Feedback Control Question: Finding compensator numerator (B(s)) and denominator (A(s)) polynomials to satisfy a specific requirement
I wish to find the polynomials B(s) and A(s) in the following compensator equation:
A(s)D(s) + B(s)N(s) = F(s)
Given,
$$N(s) = s - 2$$
$$D(s) = s^2 - 1$$
$$F(s) = s^2 + 3*s + 4$$
Condition
The degree ...
1
vote
0answers
19 views
how do i formulate a kalman filter for an upwash coefficient?
I want to make a kalman filter that will estimate the upwash coefficient $C_{\alpha_{up}}$
my state vector: $ X_k=[u \ v \ w \ C_{\alpha_{up}} ]^T $
My measurement vector: $ Z_k =[\alpha_m \ \beta_m ...
5
votes
2answers
315 views
Minimal realization of a MISO system
Given the following system:
$$\dot{x} = \begin{bmatrix}1 & 1 & 0 \\ 0 & 1 & 0 \\ 0 & 1 & 1 \end{bmatrix}x + \begin{bmatrix}0 & 1 \\ 1 & 0 \\ 0 & 1 \end{bmatrix} u$$...
8
votes
1answer
308 views
Why is it impossible to create an observer for this not fully observable system?
Consider a 1D point-mass moving along an axis. A force $u$ is applied as control. There is no gravity or other forces involved. The system can be described in state space equations as:
$$\begin{align}...
6
votes
2answers
244 views
Controllability of $x' = Ax + Bu(t)$ implies controllability of $\left \{ \begin{matrix} x' = Ax + By \\ y'=u(t) \end{matrix} \right.$
Suppose that the system
$$x'(t)=Ax(t)+Bu(t)$$
is controllable in $\mathbb{R}^n$, where $A$ is $n \times n$, $B$ is $ n \times m$ and $u(t)$ is $m \times 1$
Show that the system
$$\left \{ \begin{...
